Control Loops

Yes, it is. Recommended reading: "Process systems analysis and control", by Coughanowr and Koppel, any edition.

Thanks Sir.Let me put the steps that i have followed for calculating/finding the output. From the model, i will be getting the numerator, denominator of the system. Using inverse laplace transform, I will get the time domain relation between my SP and PV. This approach is hope so fine. Please know your comments.

And I have a another doubt also. When we work with the real time systems, performance will vary for different regions. So if we model the system in a region and if we use the same model for predicting/estimating the output in some other region, will it give better results?

A1: sounds reasonable.

A2: most real-world systems are non-linear. It is up to the Engineer to select gain, integral and derivative to give the best overall combination given the process conditions. Some will require "fastest response to disturbance", whereas others will require "no overshoot"; the control terms are different for these two extremes of response.

If it's a linear system, yes. Nonlinear systems can be a bit chaotic!

http://en.wikipedia.org/wiki/Chaos_theory

ALL systems are, more or less, non-linear; that is why equipment has calibration procedures and adjustments. The trick in any situation is to select the correct equipment and adjust it so that it does what is wanted. These are just about the only reasons that engineers are still in demand.

Thanks for the reply.

If non linear, wat are the methods available for my query? Experts please help

Modeling is a good way to develop a default set of parameters for startup however you must "loop-tune" the system instrumentation in the field application to offset process and environmental dynamics present at each location.